SOME NONLINEAR PARAMETERS OF PP INTERVALS OF PULSE MAIN PEAKS

摘要

PP intervals of pulse main peaks under different physiological states have different nonlinear characteristics. The chaos of PP intervals of pulse main peaks is identified by surrogate data method. With surrogate data method, which is applied to identifying the existing chaos of PP intervals of pulse, it is proved that the series of PP intervals of pulse are chaotic. Some characteristic parameters in the method are used to compare PP intervals of pulse main peaks under different physiological states. A digital signal measuring and recording device for pulse waves is developed. Nonlinear parameters (correlative dimensions, maximum Lyapunov exponents, complexity and approximate entropy) of the PP intervals of pulse main peaks extracted from pulse waves are calculated. The results show that these nonlinear parameters calculated from PP intervals of pulse main peaks are helpful for analyzing human's different physiological states.